Medium ("European") Shank

Some European-made Euphoniums, such as Willson and pre-1974 Boosey & Hawkes euphoniums, require medium shank. Medium shank is often called “European” taper.

Small Shank

Most Baritones and many Euphoniums require a small shank mouthpiece. Any small shank mouthpiece (including those made for trombone) will fit a baritone that requires a small shank mouthpiece.

Some common Small Shank Euphoniums/Baritones are Yamaha YEP201, YEP321, YBH621, YBH321, King 623, 625, 628, Jupiter 470, 474, 468, and 464.
Also most Marching Baritones and Euphoniums require a Small Shank mouthpiece.